Various implantable medical devices can be deployed within the lumen of a body vessel using minimally-invasive transcatheter techniques. For example, implantable medical devices can function as a replacement valve, or restore native valve function. Such devices can include an expandable frame configured for implantation in the lumen of a body vessel, such as a vein. Implantable valves can further comprise features that provide a valve function, such as opposable leaflets.
Many implantable medical devices include an implantable frame having a plurality of projections extending from the surface of the frame, such as barbs or cutting edges. The projections can have one or more sharp beveled edges that can perform beneficial functions upon implantation within a body vessel, such as retaining a valve leaflet or graft material attached to the medical device or securing the medical device within a body vessel by puncturing and engaging the interior surface of a body vessel. Before implantation within the body vessel, however, projections having one or more beveled edges can inadvertently and undesirably contact and even damage other portions of the medical device, a delivery system or the body vessel.
There exists a need in the art for an implantable medical device including a removable material to form a protective covering over or around one or more edges of a projection from a medical device frame. Removable materials that dissolve readily on implantation within a body vessel but retain a desired level of durability prior to implantation are particularly desirable. For example, a removable material can be coated over a barb extending from an implantable frame, and then dissolved rapidly upon implantation in a body vessel.